886 



Yf¥« TROPICAL AeffitCtfLTURrST. 



[JUNE I, 1885. 



Acacia. These yield a bark rich iu tannic acid, and for a 

 time were a source of much profit to the colony. Owing 

 to the improvident habit of stripping the trees wherever 

 found, without any care as to keeping up the supply 

 by new growth, the yield of wattle bark has fallen off 

 to an alarming extent. The natural forests have almost 

 disappeared, and of late years the trees have hardly ever 

 been allowed to attain maturity. Trees two or three 

 years old have been stripped ; and hence the market 

 value of the bark has been seriously diminished, though, 

 as Mr. Brown says, "no bark or other material has yet 

 been found in any quantity which contains a percentage 

 of tannic acid equal' to that of the broad-leaved wattle, 

 of which South Australia is the principal habitat." The 

 decrease in quautity and value of wattle bark is a serious 

 evil to English and Continental tanneries. It is, .there- 

 fore, uumistakably evident how important for the colony 

 is the restoration of this important product. Two species 

 are available for cultivation— the Accaeia pycnantha, or 

 bro ad-leaved wattle, which may reach 25 ft. or more in 

 height, and a foot iu diameter; and the A. decurrens, 

 or black wattle, which grows to a height of 40 ft. or 

 50 ft., and to a diameter of 20 in. Not so rich in tannin 

 as the broad-leaved wattle, it is yet reckoned that 1J lb. 

 of A. decurrens bark is equal iu its tanning results to 

 5 lb. of English oak bark. There are two other species 

 named, but of minor importance. Mr. Brown enters into 

 copious details as to the management of wattle inelosures, 

 and anions other things notices the curious fact that 

 the wattle springs up abundantly after bush fires, though 

 naturally the seed may remain in the ground for several 

 years before its husk is sufficiently saturated to allow 

 germination to take place. Hence apparently was suggested 

 the plan of subjecting the seed before sowing to the 

 operation of a slow fire, so as to slightly crack the ex- 

 tremely hard outer covering without injuring the embryo. 

 Soaking in hot water from 150° to 212°, and even boiling 

 for one to seven minutes, were also found effectual, the 

 seeds germinating in about three weeks. Supposing that 

 the seeding has been properly accomplished, and the 

 young plants properly attended to, Mr. Brown reckons 

 that with an average of 1,000 trees to the acre, and 

 bark at £5 per ton, there should be at the end of seven 

 years, on 100 acres, a clear profit of £1,100. There are 

 three or four other tan-yielding trees indicated as suit- 

 able for cultivation; but at present the likelihood of 

 their bsing utilised seems small. — Field. 



NOTES ON SILK-PRODUCING BOMBYCES 

 BEARED IN 1884. 



BY ALFRED WAIT.T.V. 



Attacus atlas. — No success whatever was obtained with 

 this species; at least, there was no possibility of obtain- 

 ing fertile ova for the rearing of the larva:. From a 

 few cocoons of the large Himalaya race, which I had left 

 from the year 1S83, two female moths emerged ; the first, 

 on the 6th of July, was an imperfect specimen; the second, 

 a perfect and splendid specimen, emerged on the 21st 

 of July. From a number of cocoons of the Ceylon race, 

 three moths only were obtained ; a female on the 4th of 

 September, a male on the 9th, and another male on the 

 20th of the same month. A small case of Atlas cocoons, 

 which I received on the 25th of September, contained, to 

 my great surprise, the largest proportionate number of 

 live cocoons I ever reeived from that tropical country; 

 the cocoons which had not hatched, and they were in a 

 majority, are the largest I ever received from Oeylon; 

 the larvre were reared on growing cinnamon trees. ( in 

 the contrary, a case containing 111 cocoons, received on 

 the 13th of November from the same country, only con- 

 tained a few live cocoons, all the others having hatched 

 during the voyage. The box was full of broken wings 

 and dust. . 



On the 18th November, 1881, I received from my cor- 

 respondent in Ceylon two most interesting letters on the 

 rearing of Attacus atlas, and Antherea mylitta, from which 

 I 'shall reproduce the most important communications, 

 6ome being from my corn spondent's wife, who this year 

 has conducted the rearing with the greatest ability and 

 success. Writing on the 12th of October, my correspond- 



ent says :— " The Atlas cocoons I sent you are better than 

 those previously sent, as the larvte were reared on grow- 

 ing cinnamon bushes under a net in the open air, whereas 

 the previous ones had been kept all their life on cut 

 milnea branches inserted in water. The latter plan does 

 well enough for the production of cocoons for manufactur- 

 ing purposes, but the moths are not so large and strong 

 as when the larva? have been kept on growing trees. 

 There would be no question about its being better for 

 any purpose to feed the larva? on growing trees, were it 

 not that in this country it is indispensable to cover the 

 trees with netting, and it is doubtful if it woidd be re- 

 munerative to cover iu a .whole plantation that way. 

 You will observe that the cinnamon seems to produce a 

 silk of superior quality to other trees. I have always 

 thought the silk of the Atlas better than that of the 

 Mylitta, if the former could only be utilised ; I had almost 

 despaired of over being able to make anything of it, be- 

 cause Atlas cocoons cannot be reeled, and they are so 

 tough in their natural state, that they would break the 

 teeth of a carding machine. Only a week ago, however, 

 I did succeed iu drawing out the silk from the Atlas co- 

 coon, and it was more by accident than by good manage- 

 ment that I found out how to do it. Some time ago I 

 boiled, with carbonate of soda, some empty Atlas cocoons 

 along with Mylitta ones containing pupa? that had been 

 long dead, and were quite dried up. The Mylitta cocoons 

 were softened by the boiling, but the Atlas ones remained 

 unmanageable; so I put the lattei in a stoppered bottle 

 to steep in the water they had been boiled in. I examined 

 them after some days, aud the steeping had not had any 

 effect on them. Then I forgot about them for two or 

 three months, and I found them last week after I thought 

 they had been thrown away long ago. They smelt very 

 nasty, but they were quite soft, so that the fibre could 

 be easily drawn out. I do not know whether the effect 

 was due to the carbonate of soda or the decoction of 

 Mylitta pupa?, or if prolonged steeping in pure water 

 would have had the same result ; but whatever the cause 

 may have been, the effect was very satisfactory. I send 

 you a sample, aud if you pull out the silk from the 

 open end of a Tv.ssv.r cocoon, and compare the two 

 samples, you will see that the Atlas is more soft and 

 lustrous than the Titssur. The Atlas is dark in colour, 

 but the colour is not in the silk itself, as it is quite 

 white when it comes from the mouth of the silkworm, 

 and is stained by the fluid which the insect discharges 

 upou it afterwards, so that it could be made white by 

 bleaching. Only four cocoons are required to produce the 

 quautity of silk in the sample sent. The Atlas moth is 

 more easily bred than the Tussur, as the larva? do not 

 move about so much, and the moths are very quiet, allow- 

 ing themselves to be handled and carried about with- 

 out attempting to fly away.'' — Journal of the Society of Arts. 



VIOLET CULTURE. 



Locality aud soil hove undoubtedly much to do witli 

 the success obtainable iu the culture of violets, for in one 

 place they may flourish, while in another they require 

 skill aud much coaxing to bring them to anything like 

 perfection. One thing, however, is certain, Viz., that grow- 

 ing violets in crowded tods, where the crowns get hut 

 little light aud air, is not likely to favour the production 

 of flowers. See how violets grow naturally, aud you mil 

 gain a pretty correct knowledge of what they, in one 

 point at least, require. Nature has given them the means 

 of avoiding overcrowding, and of insuring to each plant a 

 position favourable to its welfare. By means of the creep- 

 in- sb in, the .young plant which is commencing life on 

 its own account is removed far enough away from its fel- 

 lows to admit of the enjoyment of a plenteous amount 

 of light, air, and even sunshine, aud seedlings continually 

 springing up provide against deterioration of constitutional 

 vigour. This leads one to think that violets might be 

 very easily grown from seed, aud that, where the usual 

 means of cultivating them is not satisfactory, this method 

 of doing so might be worthy of attention. Everyone knows 

 how primroses and some other hardy Bowers may be grown 

 in much perfection oil soils not naturally favourable to 

 them, when a practice is made of raising them from seed 



